Reference is made to U.S. Pat. Nos. 3,422,826; 3,452,763; 3,656,491 and 4,133,340, all granted to the present inventor, which describe cleaning machines of the type specially adapted to degreasing of automotive parts such as transmission housings, engine blocks, etc. Each of these machines consists of a cabinet structure including a lower reservoir section and an upper cleaning chamber section within which the items to be washed are disposed during the wash cycle. The bottom reservoir section contains a volume of cleaning solution such as a caustic soda solution which is heated and caused to be pumped into a system of manifold pipes through spray nozzles which are adapted to direct a powerful cleaning spray at the items to be washed. The items are mounted on a turntable which is rotated as by a turbine jet impinging on paddle wheels, so as to be impinged by the turbine jet spray and cause rotation of the turntable and the part to assure thorough and complete coverage of the part within the washing chamber.
In U.S. Pat. No. 3,656,491, this turntable is mounted on a trolley which is adapted for in and out movement into and out of the washing chamber, passing through a frontal access door to a loading station such that the parts may be loaded onto the turntable with the turntable in a position outside the washing chamber. The loading station is free from overhead machine structure, such that the implacement of such relatively heavy articles as transmission housings and engine blocks is facilitated, since hoisting apparatus may be employed to assist in loading the part. Subsequent movement of the trolley and the turntable and part through the frontal access door disposes the same within the washing chamber.
While this is relatively convenient, the movement of the trolley has heretofore been carried out manually which adds to the physical effort required on the part of the operator in performing the washing and degreasing of these parts.
While a power-operated cylinder or other means could be directly added to the trolley, this is a relatively difficult design problem since the atmosphere within the washing chamber and reservoir section is relatively deleterious due to the presence of the volume of heated washing solution, and overspray from the cleaning jets and is usually at a very high humidity in washing machines employing a water solution.
While complex linkages and separate housing for the operating structure could be devised, such operating or power mechanism should very desirably be simple in configuration such as to be modest in cost when added to the basic cleaning machine, while at the same time being highly reliable in its operation.
The front access door itself is moved vertically upwardly from its closed position to open the washing chamber for access thereto, which movement has also been carried out manually. It would be highly desirable to counterweight the same in order to reduce the effort involved on the part of the operator. While counterweighting is an advantageous approach to reduce the operating effort, such counterweighting should insure that in the event of losing one of the counterweights, that the door is not suddenly dropped or that the counterweights themselves do not fall free of the machine creating possible injury or damage to the machine.
Accordingly, it is an object of the present invention to provide a cleaning machine of the type described in which the turntable trolley is adapted to be power actuated in its movement in and out of the washing chamber, which power operating mechanism is extremely simple and is externally mounted from the washing chamber and the reservoir cabinet such as to not be subject to the corrosive conditions within the cleaning machine. At the same time, the mechanism is extremely simple in configuration such as to be able to be provided at relatively low cost and insuring reliable operation.
It is another object of the present invention to provide a counterweighting of the frontal access door in which the sudden dropping of the door due to failure of the counterweight suspension is largely avoided.